Abstract
Epitaxial layers of In 0.53 Ga 0.47 As lattice matched to InP substrates have been grown by molecular beam epitaxy. The (100) InP substrate surfaces were first oxide passivated and then thermally cleaned under 1.5×10 -6 Torr of arsenic moleuclar beam exposure (i.e., 1.24×10 14 As 4 /cm 2 sec). When they were heated to 500 °C, damage-free surfaces without oxygen and carbon contamination were obtained. The surface chemical composition as a function of the thermal cleaning temperature was studied with Auger electron spectroscopy. In 0.53 Ga 0.47 As epilayers of highly uniform composition were grown over a 7-cm 2 InP substrate using an In/Ga coaxial oven design. Reproducible In and Ga beam fluxes to obtain lattice-match condition were achieved by adjusting the aperture ratio of the In and Ga reservoirs, and the oven temperature. Net electron concentration as low as 3×10 15 cm -3 has been achieved for the In 0.53 Ga 0.47 As layers.